<template>
  <div>
    <table border="1" width="700" style="border-collapse: collapse">
      <caption>
        购物车
      </caption>
      <thead>
        <tr>
          <th><input type="checkbox" v-model="isAll" /> <span>全选</span></th>
          <th>名称</th>
          <th>价格</th>
          <th>数量</th>
          <th>总价</th>
          <th>操作</th>
        </tr>
      </thead>
      <tbody>
        <tr v-for="(item, index) in goodList" :key="index">
          <td>
            <input type="checkbox" :checked="item.checked" @click="checkFn(index)" />
          </td>
          <td>{{ item.name }}</td>
          <td>{{ item.price }}</td>
          <td>
            <button @click="subFn(index)">-</button>
            {{ item.num }}
            <button @click="addFn(index)">+</button>
          </td>
          <td>{{ item.num * item.price }}</td>
          <td>
            <button @click="delFn(item.name)">删除</button>
          </td>
        </tr>
      </tbody>
      <tfoot>
        <tr>
          <td>合计:{{totalSum}}</td>
          <td colspan="5"></td>
        </tr>
      </tfoot>
    </table>
  </div>
</template>

<script>
export default {
  data() {
    return {
      goodList: [
        {
          name: '诸葛亮',
          price: 1000,
          num: 1,
          checked: false,
        },
        {
          name: '蔡文姬',
          price: 1500,
          num: 1,
          checked: false,

        },
        {
          name: '妲己',
          price: 2000,
          num: 1,
          checked: false,
        },
        {
          name: '鲁班',
          price: 2200,
          num: 1,
          checked: false,
        },
      ],
    }
  },
  methods: {
    subFn(i) {
      this.goodList[i].num > 0 ? this.goodList[i].num-- : 0
    },
    addFn(i) {
      this.goodList[i].num++
    },
    delFn(name) {
      this.goodList = this.goodList.filter(item => item.name !== name)
    },
    checkFn(i){
      this.goodList[i].checked = !this.goodList[i].checked
    }
  },
  computed:{
    isAll:{
      get(){
        return this.goodList.every(item => item.checked)
      },
      set(val){
        this.goodList.forEach(item => item.checked = val)
      }
    },
    totalSum:{
      get() {
        return this.goodList.reduce((sum,item)=>{
          if(item.checked) return sum + item.price*item.num
        return sum
        },0)
      }
    }
  }
}
</script>

<style></style>
